Train-control system



Dec. 7 19 26. 1,609,764

E. F. NICHOLS v TRAIN CONTROL SYSTEM.

Filed April 29. 1921 v 3 Sheds-Sheet 1 To lrae Q! i aea' canffral c/ru/ff E. F. NICHOLS TRAIN CONTROL SYSTEM Dec. 7 1926.

Filed April 29, 1921 5 Sheets-Sheet 2 in 5 4 2 4w? 3 mm. M Q 9 t 0 MW E 6 a 5 l, a 0 a Z m I S 3 M 1 m w 5 w n 1 O S H L 2 m m M n V w w ma N w E ,M n 3536 QwwQm m P mm HER kl, mm, I lhll m m \l N .mUk Qtm Dec. 7 1926.

Patented Dec. 7, 1926.

UNITED- STATES Parent over-ca,

ERNEST FOX NICHOLS, OF CLEVELAND, OHZO, ASSIGNOR- F GNE-FOUE'II-ITO' PAUL A.

BLAIR, OF'WASHINGTON, DISTRICT OF COLUIWBIA; KATHARINE VF. NICHOLS EX- ECUTRIX OF THE SAID ERNEST FOX NICHOLS, DECEASED.

TRAIN-CONTROL SYSTEM.

Application filed April 29, 1921.

This invention relates to improvements in automatic train control systems with reference more especially to systems of the above character in which the speedof the train and the relative positions of the. block signals, as well as the rate of movement of the train relativeto the signals, are controlled.

One of. the objects of the present invention is to provide a. simple, reliable,. 3ractical and efiicient automatic traincontrol systam of the above general character which may be installed'ata minimum. expense and in which a large part of the. apparatus ordinarily in use. and operation may be utilized without m extensive alterations.

A further object is to provide an automatic electro-magnetic control system and associatedtraincarried parts thatwill operate regardless-ofthe speed of the trainland so povsitioned. and arranged asto permit the operation regardless of Whether the engine is backing or. goingv forward.

Aiiirther object is to provide a system of the above general character which will be unaitectedby weather conditions or dust and dirtor snow and ice asso frequently occurs in railway systems now in use.

A'. further objectis to provide eflicient apparatus of the above general character which willjoperate without mechanical contact be. tween the track side mechanism and thetrain carried mechanism.

Other objects will be in. part'obvious and in, part hereinafter pointed out- It isknown that .there are locomotives now equipped. with. types of automatic control which, when actuated mechanically, operate.

in one position to. applythe brakes and in another position tooperate thebrake and also to cut oflfTthe steam to the engine, or

equivalent motive means, thus bringing the train .to a. stop. By means disclosed in the present invention, however, such operations are. performed automatically without mechanical contact.

The. present invention does not compre hendany broad type of train carrying cont-rol mechanism, but. it deals in the special application herein described, with magnetically operatedtrack} side signalling mechanism and with associated magnetically oper- Serial No. 465 615.

ated circuit breaking and circuit closing mechanlsm attached to the train and ad usted to actuate the train control mechanism carriedby the engine. But the invention is term is to be given the appropriate interpretation.

In order that a clearer perception may be had ofthe present invention, drawings have been appended and form a part of this disclosure, wherein similar reference characters denote corresponding. parts throughoutthe several views.

In the accompanying drawings,

Fi ure l is a diagrammatic view of that part of the device attached to the train which is adapted to open or close a circuit as it passes relatively to the setting of the track side mechanism. thereby to actuate the the speed control and air brake mechanism carried by the engine;

Figure 2. is a vertical sectionalview showing the mounting of the elements shown in Figure 1';

Figure 3 is a diagrammatic view showing sections of four blocks of track and the associated track side signalling. and speed controlling mechanisms;

Figure 4 is a diagrammatic view showing the track side magnetdevice; and

Figure 5 is a cross section through ss of Figure 4.

Referring now to Figure 1, wherein is shown the arrangement and wiring of the magnetic relay parts 1, 2 and 28, which correspond to those parts similarly designated in Figure 2, the part'l is a non-magnetic metallic plate in which a magnetic needle ismounted in a suitable bearing as at O. This magnetic needle NS is carefully balanced by inertia near its middle point so that when mounted by process of trial of error in the bearing, tapping or jarring of the frame 1, at any point, or in any direction, will not cause the needle to rotate about its axis. Two knife edged contacts at c, 0 are attached to, but insulated from, the plate 1. Into borings in the plate 1 are driven two retentive members such as small short iron rods a and a. The portion of these rods projecting above the surface of plate 1 may have various forms depending upon the use for which the device is employed and the weakness or strength of the magnetic forces to which the device is intended to respond. The magnetic needle NS is heavily plated with gold, platinum or other good contactmaking material. The contacts 0, c are placed in such relation to NS that when NS is in a nearly horizontal position it will make a good electrical contact with c and, when in an inclined position, will make a good electrical contact with 0'.

The function of the two soft iron rods a and a is to hold the needle against the knife edge contact at 0, which is so adjusted that the poles of the needle NS come very close to a and a, but do not actually touch them. The size and form of the retentive members a, a are so chosen that their attraction will hold the needle in contact at 0 against the deflecting force of the vertical component of the earths magnetic force and against small magnetic and mechanical disturbances. They are, however, so chosen in position and size and form that the magnetic impulse to which the device is intended to respond will pull the needle away from them, thus breaking the contact at c. The character of the attracting forces of the re tentive members at a and a for the needle are controlling only when the poles of the needle are close to the armatures and they loose sensible influence upon the needle as soon as the needle has been rotated through a moderate angle. Hence, a magnetic deflecting force of extremely short duration, due to magnetic road side devices, passed at high speed will deflect the needle by a sufiicient angle to remove it from the sphere of attraction of a and a, and the vertical component of the earths magnetic field will then draw the needle down until its progress is arrested by the knife edge contact 0.

The influence of the soft iron retentive members on the needles may be altered and varied by changing their form as well as their positions. In addition to the simple straight rod shown in Figure 1, I may bend the rod in the form of a right angle so that the portion in front of the plate 1 and in the plane of the needle may have the form of a short arm a shown in dotted lines, Fig. 1. This will enable the bent red at a fixed distance from the needle to exert a firmer hold upon it than the form of retentive members in Figure 1, and by rotating these arms between horizontal and vertical positions. varying degrees of control can be obtained.

Part 28, Figure 1, is a horizontal coil of wire completely surrounding the needle and its mounting. hen battery terminals are connected to 3 and 7, a cturrent is sent through coil 28 creating a magnetic field. which will independently operate the device, so that if 5-6 be an open circuit and the current sent in one direction through the coil, this circuit can be closed by the magnetic action of the coil current. Likewise circuit 1-4) may be opened or closed by sending a sufiicient current through coil 28 in one or the other direction.

Figure 2 is a median or central vertical section of the complete mounting of the device shown in Figure 1, as arranged for attachment to a moving train, A casing of bronze or other non-magnetic material 16, is closed by a hinged door parallel to and in front of the plane of the section shown. This bronze casing is divided into an upper and lower compartment by a horiZontal partition, 17, and is provided with ears, 21, shown attached to horizontal steel bars, 22, by bolts and nuts, 24 and 23, respectively. These steel bars are prcferal'ily attached to the rear truck of a locomotive tender and extend outward to a point 16 to 20 inches from the rail over the tie ends. This position on the tender is preferred because it is further outside the magnetic influence of the more massive steel parts of the locomotive. This device is duplicated in a similar position on the other side of the train, the device on one side of the train being connected to operate the brakes and that on the other side to operate the automatic speed control mechanism carried by the engine.

The plate 2 to which plate 1 is attached is secured to a cover plate, 19, which serves as the lid of a glass vessel, 27, and a gasket. 26, is positioned between 19 and the ground rim of 27. On plate 19 is soldered a small brass receptacle, 29, enclosing a hollow space, 31. There is a small opening 12 in the bottom of this receptacle which connects the opening 31, with the chamber in jar 27. The part 29 is closed at the top by a screw, 8, through which is bored a capillary opening, 13, funnelled at the top as shown. To prevent moisture and dust from getting into the bearings of the device and at the same time to serve the purposes of uniform lubrication. the glass jar 27 and the space 31 are completely filled with kerosene or other suitable emersion liquid. This liquid also, in a measure, prevents sudden jars or shocks from loosening the hold of the armatures a. (4 upon the magnetic needle NS. Opening 12 is funnelled to allow any small air bubbles which form in. the: liquid to escape block, 20, held together by a massive lead back, but the front is left open for a more convenient inspection of the device. Into the top of this leadblock two brass bushings, 10, are screwed and .into these bushings again are threaded brass-rods, 11. The axes of theserods lie in the same vertical plane as the center of gravity ot the lead block andparts attached'thereto. A brass strip, 9, fitting over these rods is pressed down upon the top of the receptacle 29 by nuts, 14 thereby to-compress the gasket 26 and make a liquid tight joint. Through the horizontal partition 17 are holes. 18, considerably larger thanthe rods 11. In-these holes,.projecting rims, 30, are attached, and, fitting over the lower projection of these rims and again over the outside of the nuts 14 are two coiledtrain operationare' mainly either up and down, due to rail joints or unevenness in the track, or'areforward and backward, due to starting and stopping the train. and to bumping. A; lighter rubber cushion,..n0t

shown, is inserted between the back of the lead block 20 and'the housing 16, and a. similar rubber cushion, .mountedon the inside ofthe' door, is provided to press against the lead block when the door isclosed. Ward and backward shocks may befurther checked'it necessary by horizontal coiled springs inserted between the ends of the lead block 20 and the front and back vertical walls of the housing 16. The axes of all springs li'e'in the vertical plane which contains-'tliecenterof gravity of the lead block and all'parts attached thereto. This is to prevent sudden shocks from. producing any rotationot" the block 20.

Figured shows a longitudinal. section, in which NS is a permanently magnetized steel bar or bundleofbars; G represents coilsof Forcopper wire arranged aroundthe permanent magnet forming a nest, as shown in-lBigure 5, which represents a cross section at ss,. near'the top ofFignre 4.

If contact is made by closing the bat tery circuit by the key at K, Figure 4', or otherwise, an electrical current maybe sent." through the coils from battery B in such. direction and of such intensity, goVernedLby" th'ecoil resistance and voltageor by an aux 7 iliary variable resistanceR, that the total? magnetic effect of the permanent magnet NS" upon a magnetic object-at short distance: from its pole maybe reduced tozero, that is, thepole strength and external field of the magnet, is neutralized or diverted. By reversing the direction of the current, the external field may-be-correspondingly increased. The current in- Figure 4: is sentthrough the coils O in such direction as to make eachcoila'magnet with poles opposite in sign to the poles of theper manent magnet; Thus, as-indicatedinrth'e figure, the north pole. of the permanent. magnet-is at the top and the south pole at the bottom, but the south poles ofthecoils are at the top and the north poles at the bottom, as indicatedby thedotted letters N and S, the dotted lines-about the-twoends of the system representing;magnetic 9513 lines of force. At-t-he top theseli-nes of force issue from the'n'orth pole. of the permanent magnet and are immediately drawn into the coils C, while at the bottom lines of force issue from the coilsG and arev drawn. into the south. pole of the-pern1a-- nent magnet. The coilsenergized by a current as here shown act. in away similar to the soft-iron bars or keepers used-on permanent magnets to gather insthe enternal field of a magnet and delay the'loss of its strength byv age.

lVliile these coils have eflfectotneutrale' the external magnetic field of the-- permanent .magnet, they do more than mere keepers'and tend to magnetize the pern'ia nent magnet morestrongly. Thus the mag.- netic influence of the permanent magnet an be reduced without-weakeni-ng itsperemanent magnetization. ()rdinarily when it is desired to weaken temporarily the strength of the permanent mz-ignetbymeans of a coil carrying current, the wire wrapped directly around the.n'1agnet,'-.forms ing a coil with the magnet at-its axis, and if an electric currentzbe sent through. such: a coil in a direction to weaken. the external field of the permanent magnet, the effectof the magneticfield of the coil is iir'su'ch. direction as to demagnetize the permanent magnet or weaken it permanently. Furthermore, the magnetization of a permanent magnet tends to become. weaker with time andthismethod o1": Wrappingthecoil. carrying current directl around thcpcr- &

of the current.

Such a device. therefore, cannot be relied upon to operate in a durable and trustworthy manner, whereas the form herein disclosed, namely, a nest of coils arranged as shown around the permanent bar magnet, tends to strengthen the permanent magnetization of the bar and thus to arrest the aging proccss referred to above.

There are many possible uses for the combination of permanent magnet and wire coils herein disclosed, but for purposes of illus tration rather than limitation, the combination is herein described in its application to a system for transmitting signals from the roadside to a moving railway train.

For the operation of this system, mag netically responsive devices of the character illustrated by Figures 1 and 2 are carried on the moving train and magnets of the type illustrated by Figure 4, connected to batteries by selected control means illustrated by Figure 3 are placed at intervals along the roadway. If no current flows through the magnet coils, the permanent magnets will act upon the magnetically responsive devices on the train and transmit a signal and automatically operate auxiliary mechanisms for speed control or for applying brakes to the train or for operating signals in the engine cab. None of these three last named types of mechanism are, however, any part of this invention. If no speed control is to be exercised or b'ake applied, a current of such magnitude and direction is sent through the nest of coils as will neutralize the field of the permanent magnetat the shortest passing distance between it and the magnetically responsive device carried by the train. In this case, the train will pass without incident.

Two of the devices illustrated by Figure 2 are carried by the train. One of these, mounted on the right rear truck of the locomotive tender, is put in electrical connection with a speed control device, which specifically is no part of this invention except as it enters into the complete construction, the other, mounted on the left rear truck, is electrically connected to an auxiliary mechanism operating the air brakes. The magnetic units shown in Figure 3, embodying the magnet and coil devices, are so disposed that the herein disclosed devices carried by the train will pass directly over them and within the space necessary to respond to their magnetic influence, that issay 4 to (3 inches.

For an understanding of the operation of the roadside or track side mechanism, reference is here made to Figure 3. The horizontal dotted lines, 32 and 33, indicate the left and right rails of one track of a double track railroad. It is to be understood, however, that the device can also be adapted to operate on a single track railroad. The sections of the track, E, F, G, H, represent the ends of tour consecutive blocks of track. The parts E, F, G, are signal semaphores operating automatically on the well known block signal system. The parts 3%, 35, 36 and 37 shown schematically are permanent magnet units employed at the end of one block to operate speed control or brakes on approaching the beginning of the following block. These magnetic units consist of the hereinbetore described permanent magnets surrounded by electric coils, the coils being operated by a battery which may be the same battery used to operate the block signal semaphores. In the system which is here being described, the current in the coils surrounding the permanent magnets is used simply to neutralize the effect of the permaient magnets, notto increase it. The potential from the battery 38 is applied through the dial commutators 39 to the electric coils nested about the permanent bar magnets at 34, 35, 36 and 37. This type of dial commutator consists of two conducting bars 40 and 41 attached at right angles to, and insulated from, each other and rotating about an axis 42. Bar 40 is in constant sliding con tact with a copper semi-circle 43 permanently connected to, say, the negative pole of the battery 38. Bar all is in similar constant sliding contact with copper semicircle 4-4, which is permanently attached to the other pole of the battery. In a semi-circular arrangement are located equally spaced contacts 45, 46, 47, 48 and 49, which are brought into selective connection with the battery terminals by the rotating bars 40 and 4:1. The dial commutators thus described can be operated by the same mechanism that operates the automatic block signal semaphores or they can be operated by wholly independent circuits of similar character, if desired.

It the dial commutator 39 is set as shown, the two permanent magnets 36 and 37 of that unit, having their south poles up, will be neutralized by the current from the battery through the dial commutator in the wiring scheme shown. Neutralization of these two magnets is indicated by leaving the circles which represent them blank. the device carried by the train is operating as a closed circuit relay, as in circuit 56, Figure 1, it requires the south pole of a magnet below it to break the circuit. The north pole of a magnet below it not only will not break the circuitbut, if the circuit be already broken, the north pole of the magnet below it will close the circuit. Similarly, when the device carried by the train is operating as an open circuit relay, as in cir- Now, when This automatic closing of circuit is. convenient and useful when the train: passes:

out of'fthe blockunder speed controlon toa clear. block, Therefore, in the case shown at unit E, the south pole, magnets, being,

neutralized, will not break the circuit of thetrain dev ce. Thus, if a train approaches;

in the direction: indicated'by the arrow, upon,

coming in View of the semaphore: of that unit, clear way will be. indicated and the train will pass. freely out of block Einto: block F havinga clear signal and" the speed control and brakev devices held in their, normal positions.

The dial; commutator 39 shows, the connections. which. will, let the. train pass: fromthe brakes, butwhifchv will break the circuit ofthe speed'controlidevice onthe right side of the train. by leaving, unneutralized' thepermanent'magnet pole S 37... Thus,.whenthe; train approaches the. end of block F, before entering block. G, the. semaphore shows, caution? and. the train. cannot proceed along, the. block GL at a greater speed; than that predetermined, by the special speed control mechanism.

The dial: commutator. 39 indicates the; connections by; which. the. north. permanent magnet. poles on bothsides of the track are neutralized. and the corresponding south poles unneutralized; Therefore, to the, speed control device which was. previously in operation is added thebrakedevice and as the train approaches the end of block" Gr, before. entering. block. H,. the; semaphore shows stop andithe. train i'sbrought to-a sto r fter brakes have beenapplied, in order to start the train, it will be necessary: topress-an electric contact 50'which will send a current through thecoili 28,: Figure 1,. and

thereby recock the, brake control device;

This recocl'ring? isv effectedthrough a key closing circuit 51 between. the. terminals 3. and 7, v in which circuit is connected the auxil'liary battery 52; The'completed circuit 56 inclndesa relaybattery. 53 adapted toenergize a coil. 55L which. controlsv an, arm ature 55, to open abrake or. speed controil circuit 56', shown schematically in Fig. 1. The closing of this relay breaks the circuit" 56 controlling a speed reducing device inthe engine cab, as, for instance, a brake system on the engine, ora regulation of the steam control thereofv When. the relay battery- 53 is connected with the-terminals 45 this circuit acts. asacircuit closer for the brake or speed control circuit 56, for the coil 54;" is, then energized to. urge the 'armature 55 in the opposite direction to complete the circuit 561" When the brake control; device; has been; recocked, the speed control; device remains operative: throughout block; unless it is. also; recocked- Reoocking; keys may,- be located: eithen in; the engine cabor at a point; where. the engineer will have to descend fromhis a to th trackside to operate them. If

the engineer heeds. the semaphorefsignal G! and steps before reaching. the magnets. S-36iand: S 3,7.,. and; waits for! caution; signal-,- bllfigilllilOHlfitlC speed control. will: go: into openatio1i,;or-"in this case, will" continue in: Operation. for the block H.- semaphore; Gg goes; from; stop? to clean, h tra n; i be". left. Wholly in the engineeu s handsandhe can: speed.

When; a train is; drawn; by a backing engine, the. speed control. mechanism: carriedifby; the. tender can; be. connected to the brakes by the: operation. ofa; reversing switch and likewise, the device used for operating. the; brak s in; forward tragveli can be thrownv over to speed controli by the reversing switch, so; that; the; system. will: operate-- as: before.

Permanent-i magnets are shown as. the nucleus of the trackside unites [for the. reason. that if; the battery supplying; coil currents should: fail, its failure could not cause an accidenhbut; would simply cause the/train devicezto throw on; the-brakesand; bring the. train to rest. This is; the type.

of precaution which is followedrin; the autos matic blocksignal; systemv whereby, if. the mechanism operating the semaphore fails, the; semaphore; always; shows stop. For the same reason; the magnetic relay, Figure 1,. is operated on a-closedi circuit, 56, con.- taining a. batteryand armature 5,5 which. operates speed control: or brakes. Thus; whenever the circuit 5 6; is'broken. or the, battery contained in it fails. in potential, speed control and brakes go on automati;

cally.

It is: believed that; adescription of the.

operation of the general system will be unnecessary in view of the full andcom,-. plete disclosure above. The invention as a whole is admirablyv adapted for; the purpose for which it isv intended inasmuch as;

it is compact, reliable and: efiicient: for use.

and-operations and designed toaccomplish amen others all of the objects andi advantages set forth herein.

Having thus described what I claim is 1. I-n-a system ofthe character. described, in combination, a member adapted; to be. carried by an engine including a magnetic needle, contacts adapted to be engaged by said needle and retentive members associated with the needle, said: retentive mem bers. comprising soft iron core members disposed alternately and adjacent the ends my invention,

Again, if;

proceed at full;

of said needle and adapted by their inherent attraction to maintain the magnetic needle in a normally fixed position, to engage one of said contacts, against the earths' magnetic force, which tends to rotate said needle away from said normally fixed position.

2. In a system of the character described, in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, retentive members on the support disposed alternately of the needle and in close proximity to which said needle moves as it swings about'its axis, said retentive members comprising soft iron cores adapted by their inherent attraction to maintain said needle in a normally fixed position against the earths magnetic force, a contact engaged by said needle when in said normally fixed position and a contact adapted to be engaged by said needle when the needle swings from its normally fixed position. 'i g 3. I11 a system of the character described, in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, contacts adapted to be engaged by said needle, retentive members on the support in close proximity to which said needle moves as it swings about its axis, and a coil associated with said needle and its sup port adaptedto move the needle from one position to another when said coil is energized by an electric current in the appropriate direction.

4. In a system of the character described, in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, contacts adapted to be engaged by saidneedle, retentive members on the support in close proximity to which said needle moves as it swings about its axis, a coil associated with said needle and its sup port adapted to move the needle from one position to another when said coil is energized, by a current of appropriate polarity, and a casing of substantially shockproof construction in which said needle is mounted. 7

5. In a system of the character described, in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, contacts adapted to be engaged by said needle, retentive members on the support in close proximity to which said needle moves as it swings about its axis, a coil associated with said needle and its support adapted t o move the needle from one position to another when said coil is energized by a current of appropriate direction, a casing of substantially shock-proof construction in which said needle is mounted, and means for securing said casing to an engine or other part of train.

6, In a system of the character described,

in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, contacts adapted to be engaged by said needle, retentive members on the support in close proximity to which said needle moves as it swings about its axis, a coil associated with said needle and its support adapted to move the needle from one position to another when said coil is energized by a current of appropriate direction, a casing of substantially shock-proof con struction in which said needle is mounted, means for securing said casing to an engine or other part of train and a track side mechanism adapted to move said magnetic needle under certain conditions as the same passes over said track side mechanism.

' 7. In a system of the character described, in combination, a support, a needle adapted to swing in a vertical bearing mounted on said support, contacts adapted to be engaged by said needle, retentive members on the support in close proximity to which said needle moves as it swings about its axis, a coil associated with said needle and its support adapted to move the needle from one position to another when said coil is energized by a current of appropriate direction, a casing of substantially shock-proof construction to which said needle is mounted, means for securing said casing to an engine, a track side mechanism adapted to move said magnetic needle under certain condi tions as the same passes over said track side mechanism, and means for varying the external field of said track side mechanism.

8 In a systemof the character described, in combination, a train carried member comprising a magnetic needle adapted to swing in a vertical plane, retentive members in close proximity thereto, comprising core members which by their inherent attraction maintain the needle in a normally fixed position against the earths magnetic 'Iorce which tends to urge the needle away from said normally fixed position, contacts and circuits associated therewith adapted to be closed or broken as said needle moves from one position to another, and an auxiliary circuit adapted to be energized on the opening and closing of said first named circuits.

9. In a system of the character described, in combination, a train carried member com prising a magnetic needle adapted to swing in a vertical plane, retentive members in close proximity thereto, comprising core members which by their inherent attraction maintain the needle in a normally fixed position against the earths magnetic force which tends to urge the needle away from said normally fixed position, contacts andcircuits associated therewith adapted to be closed or broken as said'needle moves from one position to another, an auxiliary circuit adapted to be energized on the opening "10. In a system of the character described, in combination, a train carriedmember com- }prising a magnetic needle adapted to swing in a vertical plane, contacts andcircuitsassociated therewith adapted to be closed or broken as said needle moves from one position to another, auxiliarycircuits adapted to'be energized on the opening and closing of said first named circuits, a track side mechanism adapted "to actuate said needle as the same passes thereover, said track side mechanism comprising a permanent magnet, a nest of coils grouped about said magnet, and means to energize said coils whereby the external field of said magnet may be neutralized.

11. In a system of the character described, the combination of a track side mechanism comprising a permanent magnet and means associated therewith for neutralizing the polarity of said magnet, said means comprising a plurality of current carrying coils grouped about said magnet, said coils adapted to be energized at will.

12. In a system of the character described, the combination of a track side mechanism comprising a permanent magnet, and means to neutralize the external field of said magnet as desired, said means comprising a plurality of current carrying coils grouped about said magnet and means to energize said coils at will.

13. In an apparatus of the character described, in combination, a casing adapted to be carried by an engine, a second casing mounted therein, means supporting one from the other whereby shocks are dampened before reaching the inner casing, a magnetic needle within said inner casing, adapted to swing in a vertical plane, and contacts associated with said needle together with circuits whereby the circuits are opened and closed as the needle swings from one position to another.

14. In an apparatus of the character described, in combination, a casing adapted to be carried by an engine, a second casing mounted therein, means supporting one from the other whereby shocks are dampened before reaching the inner casing, a magnetic needle within said inner casing", adapted to swing in a vertical plane, contacts associated with said needle together with circuits .whereby the circuits are opened and closed as the needle swings from one position to another, and a dampening fluid within which said needle is immersed.

f 15. In an apparatus of the character described, in combination, a casing adapted to be carried by an engine, a second casing mounted therein, means supporting one from the other whereby shocks are dampened before, reaching the inner. casing,.-a magnetic needle withinssaid-inner casing, adapted to .swingYinsa vertical plane, contacts associated with said needle together with circuits whereby the'circuits are opened and closed as the needle swings from one position to another, ,a dampening rflllid. within which said-needle .is immersed, and a track side me chanism adapted to actuate said needle.

16. In an apparatus of the character described, iii-combination, a casing adapted to be .carriedebyzanengine, a-second :casing mounted therein, means supporting one from the other whereby shocks are dampened before reaching the inner casing, a magnetic needle within said inner casing, adapted to swing in a vertical plane, contacts associated with said needle together with circuits, whereby the circuits are opened and closed as the needle swings from one position to another, a dampening fluid within which said needle is immersed, a track side mechanism adapted to actuate said needle, said track side mechanism comprising a magnet, and means associated therewith whereby the external field of said magnet may be neutralized thereby to affect or not affect the needle as it passes thereover.

17. In an apparatus of the character described, in combination, a casing adapted to be carried by an engine, a second casing mounted therein, means supporting one from the other whereby shocks are dampened before reaching the inner casing, a magnetic needle within said inner casing, adapted to swing in a Vertical plane, contacts associated with said needle together with circuits, whereby the circuits are opened and closed as the needle swings from one position to another, a dampening fluid within which said needle is immersed, a track side mechanism adapted to actuate said needle, said track side mechanism comprising a magn t. and means associated therewith wnereoy the external field of said magnet may be neutralized thereby to aitect or not affect the needle as it passes thereover, and means for successively selecting a plurality of said magnets comprising a selector, a battery, and means for connecting said battery through said selector to said track side mech: anism at will.

18. In a system of the character described, in combination, a plurality of magnets, positioned at opposite sides of the track, a plurality of coils grouped about each of said magnets, circuits connected with said coils, and a battery adapted to energize the coils when connected with circuits, and a selective mem-beradapted to connect various magnets with said battery in a predetermined manner.

19. In a system of the character described, in combination, a plurality of magnets, posi tioned at opposite sides of the track, a plurality of coils grouped about each of said magnets, circuits connected With said coils, and a battery adapted to energize the coils when connected with circuits, a selective member adapted to connect various magnets with said battery in a predetermined manner and mechanisms carried by an engine adapted to pass over said track side magnets, and be affected thereby when said track side magnets are energized in a predetermined manner.

20. In a system of the character described, in combination, a plurality of magnets, positioned at opposite sides of the track, a pinrality of coils grouped about each of said magnets, circuits connected with said coils, means adapted to energize the coils when connected with the circuits, a selective member adapted to connect various n'lagnets with said energizing means in a predetermined manner, and mechanisms, carried by an engine adapted to pass over said track side magnets, and be affected thereby when said track side n'lagnets are energized in said predetermined manner.

ERNEST FOX NICHOLS. 

